A Definition of Microbiology
Microbiology is a branch of biology. This is the theory of small living things (microorganisms), which are divided into bacteria, viruses, fungi and protozoa (protozoa). In general, the microorganisms in microbiology visible only under a microscope.
Microorganisms are widespread in nature. Some bacteria inhabit the inner and outer surfaces of the human body, these are non-pathogenic micro-organisms to, for they call thus produced no disease. The bacteria of the small and large intestine are even useful digestive aid since it provides, among other things important for blood clotting vitamin K. Such a union between two organisms is called symbiosis.
Also, there are microorganisms that act cause disease and are therefore pathogenic, and include, for example, the causative agent of bacterial infection and viral diseases. Living beings who live at the expense of another organism, called a parasite, to them, include multicellular animal life forms, such as arthropods and worms.
The micro-organisms in Microbiology
In microbiology four microorganisms can be distinguished, which is discussed now:
Bacteria are unicellular microorganisms that multiply by Zellteiling. They have their own Stoffwechel are to be bred breeding grounds and are surrounded with regard to their construction of a cell membrane and a rigid cell wall. Many bacteria can actively move through small appendages (flagella). According to their shape, a distinction is rod-shaped bacteria, spherical bacteria (cocci) and spiral-shaped bacteria (spirochetes). With regard to resistance to oxygen can be found aerobic bacteria which need oxygen to live, and anaerobic bacteria that live without oxygen.
Viruses have no cell structure, but rather consist of a protein coat (capsid), nucleic acids, which contain the genetic information, and possibly a case. Viruses can reproduce only by using living cells. They penetrate to it one with their nucleic acids into cells and alter cell metabolism so that it forms new viruses - so call this kind cell parasites. The affected cells are called the host cells, they perish in consequence of virus infection in the rule.
Mushrooms (fungi) as the plants have a rigid cell wall, a nucleus and are motile. In contrast to the plants they are not capable of photosynthesis, which means they can not use light to build energy-rich compounds. Mushrooms are about ten times larger than bacteria. There are over 120,000 different species of fungi that cause of which about 100 human diseases. Fungal infections commonly indicate a defensive weakness of the patient.
Protozoa have a clearly identifiable nucleus. Through this type of micro-organisms are caused mainly tropical diseases.
Therefore has an immensely important position microbiology in biology!